Radiation Imaging Techniques Research Articles

Characterization of gliding arc plasma ignition in aeroengine swirl combustion chamber

Gliding arc plasma-enhanced combustion is a relatively new combustion technology. This paper describes a gliding arc plasma combustion dome that improves the ignition characteristics of aeroengines. The ignition characteristics are studied using an experimental platform consisting of a single-combustion-dome swirl combustion chamber. A flame spontaneous radiation imaging technique is adopted to collect the C2* groups formed during the ignition process. We focus on the ignition mode, flame kernel propagation mechanism, ignition delay time, and ignition boundary of the gliding arc ignition process. The gliding arc ignition process has five stages with different characteristics: flame kernel stabilization, flame kernel expansion, intense combustion, combustion decay, and stable combustion. During the flame kernel propagation stage, the main flame kernel in the combustion dome splits into flame kernel 1, located in the recirculation zone of the upper wall, and flame kernel 2, located in the recirculation zone of the lower wall under the action of airflow. The main flame kernel reflects the direct action of the gliding arc. Unconsumed energy and active particles included in the main flame kernel are added to flame kernels 1 and 2 through sporadic splitting of the main kernel. This promotes the expansion rate of the fire nucleus in the combustion chamber. Compared with electric spark ignition, gliding arc plasma-enhanced combustion significantly widens the ignition boundary and shortens the ignition delay time of the combustion chamber. The ignition delay time can be shortened by up to 81.53% under an inlet flow rate of 55 m/s and a residual gas coefficient of 3; the ignition boundary can be widened by a maximum of 115.9% under an inlet flow rate of 5 m/s.

Point-of-care ultrasound of the inflammatory bowel disease

Background. The widespread use of portable ultrasound scanners has advanced the concept of ultrasound diagnosis (POCUS), namely «ultrasound examination (US) is performed at the bedside and is interpreted directly by a physician». Pocus is not a substitute for complex ultrasound, but rather allows the ultrasound doctor to quickly access clinical images for rapid diagnosis and effective examination and treatment of patients. Purpose – the work to identify ultrasound signs of inflammatory bowel disease (IBD) using POCUS. Materials and Methods. 70 patients aged 18 to 39 years (24 men and 46 women, mean age – 30.3 ± 13.7 years). The first group of patients included 32 people with a morphologically confirmed CD diagnosis, the second group included 38 people with a morphologically confirmed UC diagnosis. The control group consisted of 2 8 patients with no clinical and laboratory data on gastrointestinal lesions. Results. It was shown that the ultrasound can assess the thickness of the intestinal wall with sensitivity – 90.3% and specificity – 87.1% and ROC – 0.882, differentiation of the wall layers, surrounding structures (omentum, mesentery, lymph nodes), as well as the localization of the affected intestinal segment. Color Doppler Mapping (CDM) method with a sensitivity of 86.5% and specificity of 81.5% and ROC of 0.852 allows not only to assume the presence of active inflammation in the wall of the affected intestinal segment, but also to monitor the dynamics of the process during treatment. Conclusion. In this work, the capabilities of POCUS for the diagnosis of IBD were evaluated. Correct and accurate interpretation of POCUS findings is not only an important diagnostic step, but also a complement to other radiation and endoscopic imaging techniques. The main advantage of POCUS over CT and MRI is its fast availability, low cost, and high level of safety. An experienced ultrasound doctor is needed to examine the gastrointestinal tract, so training with ultrasound doctors and mastering practical skills is key to ensuring the effective use of POCUS.

Roentgenoscopy of laser-induced projectile impact testing.

Laser-induced projectile impact testing (LIPIT) based on synchrotron imaging is proposed and validated. This emerging high-velocity, high-strain microscale dynamic loading technique offers a unique perspective on the strain and energy dissipation behavior of materials subjected to high-speed microscale single-particle impacts. When combined with synchrotron radiation imaging techniques, LIPIT allows for in situ observation of particle infiltration. Two validation experiments were carried out, demonstrating the potential of LIPIT in the roentgenoscopy of the dynamic properties of various materials. With a spatial resolution of 10 µm and a temporal resolution of 33.4 µs, the system was successfully realized at the Beijing Synchrotron Radiation Facility 3W1 beamline. This innovative approach opens up new avenues for studying the dynamic properties of materials in situ.

An evaluation of consumer smartphones for generating bolus and surface mould applicators for radiation oncology.

The use of Computed Tomography (CT) imaging data to create 3D printable patient-specific devices for radiation oncology purposes is already well established in the literature and has shown to have superior conformity than conventional methods. Using non-ionizing radiation imaging techniques such as photogrammetry or laser scanners in-lieu of a CT scanner presents many desirable benefits including reduced imaging dose and fabrication of the device can be completed prior to simulation. With recent advancements in smartphone-based technology, photographic and LiDAR-based technologies are more readily available than ever before and to a high level of quality. As a result, these non-ionizing radiation imaging methods are now able to generate patient-specific devices that can be acceptable for clinical use. In this work, we aim to determine if smartphones can be used by radiation oncologists or other radiation oncology staff to generate bolus or brachytherapy surface moulds instead of conventional CT with equivalent or comparable accuracy. This work involved two separate studies: a phantom and participant study. For the phantom study, a RANDO anthropomorphic phantom (limited to the nose region) was used to generate 3D models based on three different imaging techniques: conventional CT, photogrammetry & LiDAR which were both acquired on a smartphone. Virtual boliwere designed in Blender and 3D printed from PLA plastic material. Theconformity of each printed boli was assessed by measuring the air gap volume and approximate thickness between the phantom & bolus acquired together on a CT. For the participant study, photographs, and a LiDAR scan of four volunteers were captured using an iPhone 13 Pro™ to assess their feasibility for generating human models. Each virtual 3D model was visually assessed to identify any issues in their reconstruction. The LiDAR models wereregistered to the photogrammetry models where a distance to agreement analysis was performed to assess their level of similarity.Additionally, a 3D virtual bolus was designed and printed using ABS material from all models to assess their conformity onto the participants skin surface using a verbal feedback method. The photogrammetry derived bolus showed comparable conformity to the CT derived bolus while the LiDAR derived bolus showed poorer conformity as shown by their respective air gap volume and thickness measurements. The reconstruction quality of both the photogrammetry and LiDAR models of the volunteers was inadequate in regions of facial hair and occlusion, which may lead to clinically unacceptable patient-specific device that are created from these areas. All participants found the photogrammetry 3D printed bolus to conform to their nose region with minimal room to move while three of the four participants found the LiDAR was acceptable and could be positioned comfortably over their entire nose. Smartphone-based photogrammetry and LiDAR software show great potential for future use in generating 3D reference models for radiation oncology purposes. Further investigations into whether they can be used to fabricate clinically acceptable patient-specific devices on a larger and more diverse cohort of participants and anatomical locations is required for a thorough validation of their clinical usefulness.

Regression Rate and Combustion Efficiency of Composite Hybrid Rocket Grains Based on Modular Fuel Units

This study investigated combustion characteristics of composite fuel grains designed based on a modular fuel unit strategy. The modular fuel unit comprised a periodical helical structure with nine acrylonitrile–butadiene–styrene helical blades. A paraffin-based fuel was embedded between adjacent blades. Two modifications of the helical structure framework were researched. One mirrored the helical blades, and the other periodically extended the helical blades by perforation. A laboratory-scale hybrid rocket engine was used to investigate combustion characteristics of the fuel grains at an oxygen mass flux of 2.1–6.0 g/(s·cm2). Compared with the composite fuel grain with periodically extended helical blades, the modified composite fuel grains exhibited higher regression rates and a faster rise of regression rates as the oxygen mass flux increased. At an oxygen mass flux of 6.0 g/(s·cm2), the regression rate of the composite fuel grains with perforation and mirrored helical blades increased by 8.0% and 14.1%, respectively. The oxygen-to-fuel distribution of the composite fuel grain with mirrored helical blades was more concentrated, and its combustion efficiency was stable. Flame structure characteristics in the combustion chamber were visualized using a radiation imaging technique. A rapid increase in flame thickness of the composite fuel grains based on the modular unit was observed, which was consistent with their high regression rates. A simplified numerical simulation was carried out to elucidate the mechanism of the modified modular units on performance enhancement of the composite hybrid rocket grains.

Effect of characteristic structure of nested composite hybrid rocket fuel grain on combustion properties

This work numerically and experimentally investigated the effect of the characteristic structure of nested composite fuel grains on their combustion properties. The characteristic structure comprised multiple helical grooves inside the fuel grain port, which formed during the combustion process. Three-dimensional steady-state simulations were employed to analyze the burning behavior of composite fuel grains with different scales of the characteristic structure (i.e., groove depth) of 0, 1, and 2 mm. An obvious swirl-gas flow field and large tangential velocity appeared for fuel grains with the characteristic structure, which was conductive to enhancing the propellant mixing. A larger flame region and more intense burning were correspondingly achieved, during which greater amounts of H2O and CO2 were generated than by fuel grain without the characteristic structure. Numerical results verified that the characteristic structure was theoretically beneficial to improving the combustion properties of the grains. Firing experiments were conducted using a laboratory-scale hybrid rocket engine with oxygen as the oxidizer. The flame structure and pulsation features were synchronously analyzed using a radiation imaging technique. Pure paraffin-based fuel grains with a circular port were tested for comparison. Both regression rates and combustion efficiencies of the composite fuel grains with characteristic structure scales of 1 mm and 2 mm showed significant improvement. The flame images exhibited an obvious helical shape and large area, which was consistent with the numerical analysis. Both the numerical and experimental results confirmed that the helical characteristic structure in the composite fuel grain played a key role in enhancing the combustion properties and demonstrate potential for further development.

Preface

It is a matter of great pleasure for the organizers to bring out the Conference proceedings of the 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) in Journal of Physics: Conference Series. The 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) was held during May 18-19, 2023 through HYBRID Mode at Sant Longowal Institute of Engineering and Technology, Longowal, Punjab (INDIA). The AMRP-2023 conference is an important event that brings academics and researchers from all over India to share their professional experiences, expand their professional knowledge and receive updates on the latest advances in the field of advanced materials and radiation Physics.Materials science is an interdisciplinary field which deals with the discovery and design of new materials involving the study of materials through the materials paradigm (synthesis, structure, properties and performance). The subject covers a broad spectrum of materials science research including functional materials, synthesis and processing, theoretical analyses, characterization and properties of materials. Emphasis is also placed on the interdisciplinary nature of materials science and issues at the forefront of the field, such as energy and environmental issues, as well as medical and bioengineering applications are also discussed.The Radiation Physics is highly multidisciplinary in nature and is now the backbone of the nuclear medical diagnostics. The radiation physics research covers many areas of radiation imaging techniques, fundamental studies of semiconductor radiation detectors, detector materials, radiation interaction with matter and medical physics which aims to improve knowledge and methods in the field of radiation physics and radiation dosimetry, in order to develop new radiation measurement instruments and methods for applications in research, industry and medicine.In this conference more than 150 researchers from reputed universities/institutes have shown interest in hybrid mode participation. The conference included one key note address, four plenary talks, six invited talks, and presentation of more than 130 contributed papers via online & offline mode on different aspects of the conference theme. We extend our sincere gratitude to all the authors who submitted their papers to the AMRP conference. We also like to express our great appreciation to the Keynote, plenary and invited speakers.We are thankful to Institute administration for extending all support and motivation to organize this conference. On behalf of the Conference Organizing Committee, we would like to thank the referees for their efficient and thoughtful actions. We are grateful to the members of the Organising Committee for their efforts in making and shaping the program for AMRP 2023. Particularly, we acknowledge the publishing support from the members of Journal of Physics: Conference Series. We hope that the future AMRP will be as successful and stimulating, as indicated with the contributions presented in this volume.Organising Committee AMRP-2023List of Organising Committee is available in this Pdf.

Malignancy in pregnancy: Multimodality imaging and treatment.

The diagnosis of cancer is increasingly made in the pregnant population, thought to be from the increasing average age of pregnancy and the use of prenatal fetal noninvasive screening techniques, leading to incidental detection of cancer in the mother. Complex challenges are associated with imaging, diagnosis, staging, and treatment of cancers in this patient population, which require highly specialized interdisciplinary management. This report discusses the use of multimodality imaging and safety considerations in pregnant patients, reviews the current guidelines for ionizing radiation imaging techniques, and presents a series of commonly and uncommonly encountered cancers in pregnancy with current diagnostic imaging guidelines. The authors also discuss the role of multidisciplinary management and treatment options and provide an overview of therapy-related considerations in the age of novel anticancer therapies. PLAIN LANGUAGE SUMMARY: The diagnosis and management of pregnant patients who have cancer are actively evolving as novel imaging techniques and anticancer therapies are being developed. Radiologically, there are inherent difficulties in balancing the minimization of fetal ionization while acquiring diagnostic quality imaging necessary for the diagnosis, staging, and treatment of maternal disease. Standardized imaging protocols are still being developed, with evolving imaging guidelines coupled with rapidly expanding research and development of novel anticancer therapies, which come with their side effects and complications. Caring for this patient population is especially challenging and requires specialized multidisciplinary attention.

Common Clinical signs and symptoms observed in Patients diagnosed with Thyrotoxicosis in Gujranwala, Pakistan

Aim: To assess the common clinical sign and symptoms in Patients of Thyrotoxicosis in Gujranwala, Pakistan. This study was conducted at the Civil Hospital and Salamat Hospital & Healthcare Center, Gujranwala from July 2019 to February 2020. Methods: This was a prospective study consisted of 120, male and female patients of different age groups, diagnosed with thyroid gland disorder. The Clinical features and history related to thyroid disorders was taken. Complete thyroid profile was checked in initial screening of Thyrotoxicosis.The bloodscreening for various thyroid hormonal levels,Thyroid imaging for the patients with neck swelling and clinically various thyroid function tests were done by using Radiation Imaging (Radiotracers) techniques. Aninformed consent of all patients was taken before tests and study. The data was recorded on designed Performa. Results: In this study the prevalence of Thyrotoxicosis patients was higher in females (78) than male (42) and majority of patients belonged to 31-50 years of age range. Various typical clinical sign and symptoms of Thyrotoxicosis like Goiter, sweating, heat intolerance, Hoarseness, Tremors, Diarrhoea, anxiety, hair loss, Menstrual irregularities in females, Exophthlmus, increased appetite and poly urea were observed in patients diagnosed with Thyrotoxicosis.While in blood screening, marked mean ±SD of BMI, free T3ng/dL, T4(ng/dL) and TSH(mlU/L) were found in male & female patients (table 2). Conclusion and practical implication: Thyroid casesare found high in our population. This high prevalence rate is affecting the health and quality of life of affected persons. So it is deeply felt that awareness to use dietary iodineand other remedies isa need of hour for our communities to decrease high prevalence of the thyroid dysfunctions and improve health and quality of life of the community. Keywords: Thyrotoxicosis, Radiotracers, Radiation Imaging Technique, Signs and Symptoms, TSH, T3 and T4, Prevalence.

MEASUREMENT OF ENTRANCE SKIN DOSE AND ABSORBED DOSE TO DIFFERENT ORGANS IN DUAL-ENERGY X-RAY ABSORPTIOMETRY SCANS USING THERMOLUMINESCENCE DOSIMETRY.

Thermoluminescence dosimetry is considered as an effective method in estimating the absorbed doses to organs in different imaging modalities. The present study focuses on dosimetry in dual-energy X-ray absorptiometry scans, for patients, and phantoms in various imaging centres. The cubical LiF (Mg, Ti) thermoluminescence dosemeters were inserted inside the holes of the Rando phantom slabs, to measure the absorbed dose to different organs in the whole body and lumbar scans. According to the results the maximum entrance skin dose was found to be 202.06μGy for Hologic discovery W, which uses the fan beam scanning mode. The Norland XR-800 device took the scans with a much lower dose, as it uses the pencil beam for scanning the patients. The results of the study show that the radiation beam type, patient thickness, imaging technique and scan time may affect the radiation dose received by patient.

Knowledge Regarding Ionizing Radiation Exposure Safety Among Orthopedic Surgeons at Hospitals in Al-Madinah.

Background and objective The use of radiation imaging techniques in operation theaters is essential fornumerous surgical procedures and patients' overall well-being. Radiation imaging techniques enable the surgeon to have a real-time visualization of the anatomy and to perform operations with a greater chance of success, decrease rates of patient morbidity, and enablesurgeons to obtain imaging records before the patient leaves the theater room. However, with the increased use of imaging techniques in orthopedic surgical operations, orthopedic surgeons are being exposed to higher levels of radiation, and hence they can be classified as a high-risk group for occupational radiation exposure. This study aimed to assess orthopedic surgeons'awareness and knowledge regarding radiation exposure safety. Materials and methods Aquestionnaire-based descriptive cross-sectional study was conducted from January to March 2022 to assess the knowledge regarding ionizing radiation exposure safetyamong orthopedic surgeons, including consultants, specialists, and residents, at both private and governmental hospitals in Al-Madinah city, Saudi Arabia. Ethical approval was obtained from the Ministry of Health (MOH) of Al-Madinah (approval number: H-03-l.l-084). The applied statistical tests were frequency and MCT tests for univariate variables while Chi-square was applied for bivariate variables. With a 95% confidence interval (CI), a p-value of more than 0.05 was used as the cut-off value for the significance level. Results A total of 57 surgeons participated in the study, of which 57.9%were exposed to radiationtwo to three times per week. Additionally, more than half of the physicians (66.7%) were not trained to use fluoroscopy (C-arm machine). Of note, 78.9% of orthopedic surgeons reported that they used the protective apron as protective equipment, while 17.5% of them used both a protective apron and thyroid shield. However, only less than half of the orthopedic surgeons(43.9%) in our study practiced radiation safety in the operating room. Conclusion Our study revealed a lack of knowledge and awareness related to ionizing radiation exposure safety among orthopedic surgeons in Al-Madinah city, Saudi Arabia.

Radiation Dose Reduction Opportunities in Vascular Imaging.

Computed tomography angiography (CTA) has been the gold standard imaging modality for vascular imaging due to a variety of factors, including the widespread availability of computed tomography (CT) scanners, the ease and speed of image acquisition, and the high sensitivity of CTA for vascular pathology. However, the radiation dose experienced by the patient during imaging has long been a concern of this image acquisition method. Advancements in CT image acquisition techniques in combination with advancements in non-ionizing radiation imaging techniques including magnetic resonance angiography (MRA) and contrast-enhanced ultrasound (CEUS) present growing opportunities to reduce total radiation dose to patients. This review provides an overview of advancements in imaging technology and acquisition techniques that are helping to minimize radiation dose associated with vascular imaging.

Leg Length Measurement: Review

Background. Measurement of the length of the lower extremities is an important part of the assessment of the musculoskeletal system. If there is a discrepancy in the length of the legs, the accuracy of the measurement technique will determine the choice of further tactics for treating the patient. However, to date, there is no consensus among experts regarding the optimal and accurate method for assessing this clinical condition.
 The aim is to analyze foreign and domestic researches about measurement of limb length discrepancy and to determine the optimal method for measuring the lengths of the lower extremities.
 Methods. More than 70 scientific articles were selected from 1983 to 2021 in the PubMed/MEDLINE and eLIBRARY databases in Russian and English languages.
 Results. An analysis of the literature data did not reveal the optimal method for measuring the length of the lower extremities. Clinical evaluation procedures have demonstrated poor reproducibility and high measurement errors. Radiation imaging techniques also have measurement errors, additionally exerting radiation exposure on the patient. Imaging techniques such as ultrasound and MRI are described in several studies, which does not allow to fully determine all the advantages and disadvantages of these methods when measuring the lengths of the lower extremities.
 Conclusion. The study and development of new methods for diagnostics different lengths of the lower extremities, as well as the improvement of existing methods, will improve the quality of diagnosis of this pathological condition, and therefore affect the quality of the treatment for its correction.

Radiation metothds for the diagnosis of liver hemangiomas

Aim. To determine the value of radiation imaging techniques such as US, CT and MRI for diagnosing liver hemangiomas. Materials and methods. The article presents the results of radiations diagnostics of 96 patients with the hepatics hemangiomas. Patients age ranged from 16 to 73 years (mean age 42 ± 10 years). There was a significant predominance of women 78 (83.1 %). And the ratio of women to men was 4.8 : 1. The tumor occupied the area of one segment of the liver in 21 (21.8 %) cases, two segments in 35 (35.4 %), three segments - in 17 (17.7 %), four or more segments - in 23 (23.9 %) cases. Results. Non-invasive diagnostic methods are very effective and allow timely detect of liver hemangiomas in most patients. According to the material, the informativeness of radiation diagnostic methods was at least 90 %. Conclusion. MRI, in comparison to CT and ultrasound, is considered a more sensitive and informative method. But taking into account the prevalence, safety and affordability, it is necessary to give preference to ultrasound diagnostics as the primary link in radiation imaging.

Using Synchrotron Radiation Imaging Techniques to Elucidate the Actions of Hexarelin in the Heart of Small Animal Models.

The majority of the conventional techniques that are utilized for investigating the pathogenesis of cardiovascular disease in preclinical animal models do not permit microlevel assessment of in situ cardiomyocyte and microvascular functions. Therefore, it has been difficult to establish whether cardiac dysfunction in complex multiorgan disease states, such as heart failure with preserved ejection fraction and pulmonary hypertension, have their origins in microvascular dysfunction or rather in the cardiomyocyte. Herein, we describe our approach of utilizing synchrotron radiation microangiography to, first, ascertain whether the growth hormone secretagogue (GHS) hexarelin is a vasodilator in the coronary circulation of normal and anesthetized Sprague-Dawley rats, and next investigate if hexarelin is able to prevent the pathogenesis of right ventricle (RV) dysfunction in pulmonary hypertension in the sugen chronic hypoxia model rat. We show that acute hexarelin administration evokes coronary microvascular dilation through GHS-receptor 1a and nitric oxide, and through endothelium-derived hyperpolarization. Previous work indicated that chronic exogenous administration of ghrelin largely prevented the pathogenesis of pulmonary hypertension in chronic hypoxia and in monocrotaline models. Unexpectedly, chronic hexarelin administration prior to sugen chronic hypoxia did not prevent RV hypertrophy or RV cardiomyocyte relaxation impairment. Small-angle X-ray scattering revealed that super relaxed myosin filaments contributed to diastolic dysfunction, and that length-dependent activation might contribute to sustained contractility of the RV. Thus, synchrotron-based imaging approaches can reveal novel insights into cardiac and coronary functions in vivo.

Time invariance of three-dimensional morphology of equiaxed dendrite: A phase-field study

Dendrite morphology has a significant effect on solute segregation and fluid flow in bulk metallic materials. Therefore, the detailed morphological evolution of dendrites is important to better understand these processes. Recently, three-dimensional (3D) dendrite morphology has been analyzed using interface shape distribution (ISD) maps that are spanned by the curvedness and shape factor of the local solid−liquid interface in an Al−Cu alloy. Data were collected through in-situ observations using synchrotron radiation imaging techniques [J.W. Gibbs et al.: Sci. Rep., 5 (2015) 11824]. This methodology is quite effective for describing 3D dendrites. In this study, we thoroughly investigated the morphological evolution and the related ISD map of free-growing equiaxed dendrites in an Al−3mass%Cu alloy using a quantitative phase-field model. The ISD was found to differ depending on the degree of undercooling. Importantly, the results indicate the presence of a time-invariant feature after sufficient branching and growth of secondary arms, when the degree of undercooling is substantial enough to produce a bunch of branching. The time invariance is considered a universal feature of equiaxed dendrite growth.

Synchrotron Radiation-Based Refraction-Contrast Tomographic Images Using X-ray Dark-Field Imaging Optics in Human Lung Adenocarcinoma and Histologic Correlations.

The aim of this study was to evaluate the clinical implication of synchrotron radiation imaging techniques for human lung adenocarcinoma in comparison with pathologic examination. A refraction-based tomographic imaging technique called the X-ray dark-field imaging (XDFI) method was used to obtain computed tomographic images of human lung adenocarcinoma at the beam line at Photon Factory BL 14B at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan. Images of normal lung tissue were also obtained using the same methods and reconstructed as 3D images. Both reconstructed images were compared with pathologic examinations from histologic slides which were made with identical samples. Pulmonary alveolar structure including terminal bronchioles, alveolar sacs, and vasculatures could be identified in synchrotron radiation images of normal lung. Hyperplasia of interstitial tissue and dysplasia of alveolar structures were noticed in images of lung adenocarcinoma. Both synchrotron radiation images were considerably correlated with images from histologic slides. Lepidic patterns of cancer tissue were distinguished from the invasive area in synchrotron radiation images of lung adenocarcinoma. Refraction-contrast tomographic techniques using synchrotron radiation could provide high-resolution images of lung adenocarcinoma which are compatible with those from pathologic examinations.

Effect of the degree of supercooling on growth mechanism of Cu6Sn5 in pure Sn/Cu solder joint

The growth mechanism of Cu6Sn5 intermetallic compound (IMC) at Sn/Cu interface reflowed under 250 °C, 275 °C, and 300 °C for a duration of 60 s and undergoing highly pressurized air action (HP), water cooling (WC), air cooling (AC) or furnace cooling (FC) in the aftermath has been outlined. In addition, synchrotron radiation imaging technique has been utilized to in situ observe interfacial Cu6Sn5 grains growth. It has been revealed that the morphologies of Cu6Sn5 grains under HP and AC are both scallop-like, whereas the samples processed with HP and FC bear plane structure and prismatic morphologies. These revelations indicate the secondary growth of Cu6Sn5 grains during the cooling stage as the significant determinant of the final IMC morphology. Thus, continuous growth on the rough surface (M1), spiral dislocation growth (M2), and 2D nucleation and growth (M3), have been proposed to explain the observed morphologies of interfacial Cu6Sn5 grains. M1 has been recognized as the principal mechanism responsible for IMC morphology undergoing water cooling, whereas combination of M1 and M2 decide the morphological feature of interface resulting from air cooling. Finally, all of the three mechanisms (M1, M2 and M3) account for the IMC morphology corresponding to furnace cooling. As all of these three growth mechanisms are affected by the degree of supercooling (ΔT), it is inferred that the ΔT can influence the secondary nucleation of IMC at the cooling stage. With the fact that the homogeneous nucleation occurs at larger ΔT, and the relative favorability for heterogeneous nucleation at smaller ΔT; the growth mechanisms can be mapped with the degree of undercooling. Consequently, the IMC growth mechanisms proposed and their association with ΔT, can be used to obtain an appropriate thickness and morphology of IMC to improve the reliability of solder joints.

Intraoperative image guidance for lateral position surgery.

Recent advances in minimally invasive spine surgery techniques have precipitated the popularity of lateral position spine surgery, such as lateral lumbar interbody fusion (LLIF) and oblique lumbar interbody fusion (OLIF). Lateral position surgery offers a unique, minimally invasive approach to the lumbar spine that allows for preservation of anterior and posterior spinal elements. Traditionally, surgeons have relied upon fluoroscopy for triangulation and implant placement. Over the last decade, intraoperative 3-dimensional navigation (ION) has risen to the forefront of innovation in LLIF and OLIF. This technology utilizes intra-operative advanced imaging, such as comminuted tomography (CT), to map the patient’s 3D anatomy and allows the surgeon to accurately visualize instruments and implants in spatial relationship to the patient’s anatomy in real time. ION has the potential to improve accuracy during instrumentation, decrease operating room times, lower radiation exposure to the surgeon and staff, and increase feasibility of single-position surgery during which the spine is instrumented both laterally and posteriorly while the patient remains in the lateral decubitus position. Despite the advantages of ION, the intra-operative radiation exposure risk to patients is controversial. Future directions include continued innovation in ultra low radiation imaging (ULRI) techniques and image enhancement technology and in uses of robot-assisted navigation in single-position spine surgery.

In situ infiltration behavior and interfacial microstructure evolution between Al and carbon fibers

The infiltration process of Al into unidirectional carbon fiber (CF) bundles was observed using in situ synchrotron radiation imaging technique. The effects of surface metallization and matrix alloying on the infiltration behavior were studied. The infiltration process of the original Al/CF couple was a physical filling process due to the poor wettability. Thus, the observed infiltration distance presented an approximately linear increase over time. With Ni coatings, the improvement in the wetting behavior changed the infiltration process to spontaneous infiltration, and the average infiltration velocity significantly increased from 0.25 μm/s to 0.72 μm/s. The spontaneous infiltration behavior was further improved by stronger Al-Mg-Ni reaction during matrix alloying, and the velocity increased to 0.91 μm/s. For the CF reinforced Al-matrix composites fabricated by a rolling method, an improved infiltrated microstructure with few defects was obtained under surface metallization and matrix alloying due to the multi-element interfacial reaction.